Production and use of polymeric fibers is well known. Polymeric fibers have been widely used to produce a variety of articles such as nonwoven and woven fabrics. Typically, because of processing limitations, such fibers are polypropylene-based. However, such fibers generally produce fabrics that are not soft to the touch and clothing articles produced from such fabrics are uncomfortable to wear.
Various modifications to polymer compositions used to make fibers have been proposed to improve the properties of fabrics produced from the fibers. U.S. Pat. No. 5,199,885 discloses the use of copolymers of propylene and up to 5% ethylene to produce polymeric fibers and fabrics. The copolymers are produced through conventional non-metallocene catalyst polymerization techniques. The copolymers exemplified incorporate 3% ethylene. The '885 Patent discloses use of the copolymers to provide fabrics with broader melting point ranges to promote bonding in laminate structures. The Patent also discloses that the softness of copolymer laminate structures is improved.
U.S. Pat. No. 6,657,033 discloses the use of random copolymers of propylene and alpha olefins other than ethylene for the production of fibers. The reference also discloses that the copolymer may be blended with a HDPE, LDPE, or LLDPE. Metallocene catalyzed polymers are not disclosed. U.S. Pat. No. 5,571,619 discloses the propylene copolymers incorporating an alpha olefin of 5 or more carbon atoms in the production of fibers, fabrics, and films. U.S. Pat. No. 5,571,619 discloses that copolymers of propylene and alpha olefins having four or less carbon atoms are not suitable because of cold flow resistance properties.
U.S. Pat. No. 4,839,228 discloses blending non-metallocene catalyzed polyethylenes with polypropylene to produce fiber compositions. The reference exemplifies the use of LLDPE and lists LDPE and HDPE for inclusion in the blends. Melt indices of 12 to 120 for the polyethylenes are identified. U.S. Pat. No. 6,281,289 discloses the production of polymeric fibers made from blends of polypropylene and LLDPE having melt indices of less than 10. Other references disclosing the use of blends of polypropylene and polyethylenes are U.S. Pat. Nos. 6,281,289; 5,593,768; and PCT Published Application WO 95/20931.